Especially when browsers are stateless and request things at different times anyways. If you have a lot of requests, you can expect a few of them to get the HTML from one version and the javascript and CSS from another anyways, no matter your strategy.

I still think this is a valuable deployment strategy, just because you can rollback and switch deployed versions easily, which is always useful. And it's certainly better than rsyncing to a live directory, at any rate.